1. Mechanical advantage: number of times a machine________an input force
Measuring the actual forces acting on a machine
Ideal Mechanical Advantage
M.A. in the absence of friction
M.A. is always______than ideal because of _______________.
engineers often design machines that use low-friction materials and lubricants

2. The gondola uses the inclined plane formed by its supporting cable to more easily move people uphill.
The increased horizontal distance (_____________) is greater than the vertical gain in height (__________________).
The inclined cable gives the gondola a mechanical advantage greater than 1.

3. Efficiency
The percentage of work input that becomes work output is the___________________of a machine.
Because of friction, efficiency is always less than ______
If the efficiency of a machine is 75%, then 75% of the work input becomes work output
Reducing___________increases efficiency of a machine.
Roller bearings reduce friction of the rotating wheels
The bearings are also greased to reduce rolling friction

4. Efficiency
If a machine requires 10.0 J of work input to operate, then what is the work output if the machine is 75% efficient?

5. Efficiency
Engineers analyze the flow pattern of a smoke trail to determine the fluid friction forces (______ _________) acting on the vehicle. Engineers use these data to optimize a vehicle's shape for maximum fuel efficiency.